The son of the owner of one of two villas making up the consulate told Reuters that U.S. diplomats made few improvements to its perimeter security since renting it last year. What was added – barbed wire atop the garden walls and CCTV cameras – were things that he, in common with many better off Libyans, would have done for himself anyway as the fall of Muammar Gaddafi’s police state brought a new lawlessness to Benghazi.

Crucially, given how a protest on the street was followed by a crowd surging into the compound, the main entrance featured no “air-lock” – a second internal gate, common to such official compounds in hostile environments around the world, which can trap intruders who force their way inside past the first guards.

That may, to some degree, reflect choices made by Stevens himself: the ambassador’s many admirers say a low-key approach to security was one of the factors that made him an unusually effective diplomat in the Arab world, widely praised for being both intrepid and approachable by those he wished to help.